package chapt17networkProgram;

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.concurrent.CountDownLatch;

public class DownUtilFor403 {
    //定义下载资源的路径
    private String path;
    //指定所下载的文件的保存位置
    private String targetFile;
    //定义需要多少个线程下载资源
    private int threadNum;
    //定义下载的线程对象
    private DownThread[] threads;
    //定义下载的文件总大小
    private int fileSize;

    public DownUtilFor403(String path, String targetFile, int threadNum){
        this.path = path;
        this.targetFile = targetFile;
        this.threadNum = threadNum;
        //初始化threads数组
        threads = new DownThread[threadNum];
    }
    public void download() throws Exception{
        /*原代码，因403，不可用 */
        URL url = new URL(path);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setConnectTimeout(5 * 1000);
        /*文件总大小：16 肯定是不对的了 */
//        conn.setRequestMethod("GET");
//        conn.setRequestProperty("Accept",
//                "image/jpg, image/gif, image/jpeg, image/pjpeg, image/pjpeg, " +
//                        "application/x-shockwave-flash, application/xaml+xml, " +
//                        "application/vnd.ms-xpsdocument, application/x-ms-xbap, " +
//                        "application/x-ms-application, application/vnd.ms-excel, " +
//                        "application/vnd.ms-powerpoint, application/msword, */*");
//        conn.setRequestProperty("Accept-Language", "zh-CN");
//        conn.setRequestProperty("Charset", "UTF-8");
//        conn.setRequestProperty("Connection", "Keep-Alive");

        /*文件总大小：185112*/
//        conn.setRequestMethod("GET");
//        conn.setRequestProperty("referrer-Policy", "strict-origin-when-cross-origin");
//        conn.setRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7");
//        conn.setRequestProperty("Accept-Encoding", "gzip, deflate, br, zstd");
//        conn.setRequestProperty("Accept-Language", "zh-CN,zh;q=0.9");
//        conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36");

/*文件总大小：185112*/
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpGet request = new HttpGet(path);
        request.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36");
        request.setHeader("Accept", "image/webp, image/apng, image/*, */*;q=0.8");
        request.setHeader("Referer", "https://www.example.com/");

        CloseableHttpResponse response = httpClient.execute(request);
        fileSize = (int) response.getEntity().getContentLength();

        //得到文件大小
//        fileSize = conn.getContentLength();
        System.out.println("文件总大小：" + fileSize);
        conn.disconnect();
        int currentPartSize = fileSize / threadNum + 1;
        RandomAccessFile file = new RandomAccessFile(targetFile, "rw");
        //设置本地文件的大小
        file.setLength(fileSize);
        file.close();

        CountDownLatch countDownLatch = new CountDownLatch(threadNum);

        for (int i = 0; i < threadNum; i++) {
            //计算每个线程下载的开始位置
            int startPos = i * currentPartSize;
            //每个线程使用一个RandomAccessFile进行下载
            RandomAccessFile currentPart = new RandomAccessFile(targetFile, "rw");
            //定位该线程的下载位置
            currentPart.seek(startPos);
            //创建下载线程
            threads[i] = new DownThread(startPos, currentPartSize, currentPart, countDownLatch, fileSize);
            //启动下载线程
            threads[i].start();
            if (i == 3){
            }
        }
        countDownLatch.await();
    }
    //获取下载的完成百分比
    public double getCompleteRate(){
        //统计多个线程已经下载的总大小
        int sumSize = 0;
        for (int i = 0; i < threadNum; i++) {
            sumSize += threads[i].length;
        }
        //返回已经完成的百分比
        return sumSize * 1.0 / fileSize;
    }

    private class DownThread extends Thread{
        //当前线程的下载位置
        private int startPos;
        //定义当前线程负责下载的文件大小
        private int currentPartSize;
        //当前线程需要下载的文件块
        private RandomAccessFile currentPart;
        //定义该线程已下载的字节数
        private int length;
        //总大小
        private int fileTotalSize;

        private CountDownLatch countDownLatch;

        public DownThread(int startPos, int currentPartSize,RandomAccessFile currentPart, CountDownLatch countDownLatch, int fileTotalSize){
            this.startPos = startPos;
            this.currentPartSize = currentPartSize;
            this.currentPart = currentPart;
            this.countDownLatch = countDownLatch;
            this.fileTotalSize = fileTotalSize;
        }
        public void run(){
            try {
                /*原生方式*/
//                URL url = new URL(path);
//                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
//                conn.setConnectTimeout(5 * 1000);
//                conn.setRequestMethod("GET");
//                conn.setRequestProperty("Accept",
//                        "image/jpg, image/gif, image/jpeg, image/pjpeg, image/pjpeg, " +
//                                "application/x-shockwave-flash, application/xaml+xml, " +
//                                "application/vnd.ms-xpsdocument, application/x-ms-xbap, " +
//                                "application/x-ms-application, application/vnd.ms-excel, " +
//                                "application/vnd.ms-powerpoint, application/msword, */*");
//                conn.setRequestProperty("Accept-Language", "zh-CN");
//                conn.setRequestProperty("Charset", "UTF-8");
//                InputStream inStream = conn.getInputStream();

//                Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36
//                Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36

/*解决403方式1----失败 */
//                URL url = new URL(path);
//                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
//                conn.setConnectTimeout(5 * 1000);
//                conn.setRequestMethod("GET");
//                conn.setRequestProperty("referrer-Policy", "strict-origin-when-cross-origin");
//                conn.setRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7");
//                conn.setRequestProperty("Accept-Encoding", "gzip, deflate, br, zstd");
//                conn.setRequestProperty("Accept-Language", "zh-CN,zh;q=0.9");
//                conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36");
//                conn.setRequestProperty("Connection", "keep-Alive");
//                InputStream inStream = conn.getInputStream();
/*解决403方式2---能下载，但是完成量不固定，且下不完-*/
//文件总大小：185112                已完成：0.2519771813820822
//文件总大小：185112                已完成：0.2537652880418341
//文件总大小：185112                已完成：0.5066446259561779
                CloseableHttpClient httpClient = HttpClients.createDefault();
                HttpGet request = new HttpGet(path);
                //设置请求头
                request.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36");
                request.setHeader("Accept", "image/webp, image/apng, image/*, */*;q=0.8");
                request.setHeader("Referer", "https://www.example.com/");
                CloseableHttpResponse response = httpClient.execute(request);
                HttpEntity entity = response.getEntity();
                InputStream inStream = entity.getContent();


                //跳过startPos个字节，表明该线程只下载自己负责的那部分文件
                inStream.skip(this.startPos);
                System.out.println(Thread.currentThread().getName() + "---this.startPos: " + this.startPos);

                byte[] buffer = new byte[1024];
                int hasRead = 0;
                //读取网络数据，并写入本地文件
                while (length < currentPartSize && (hasRead = inStream.read(buffer)) != -1){
                    currentPart.write(buffer, 0, hasRead);
                    //累计该线程下载的总大小
                    length += hasRead;
//                    System.out.println("线程：" + Thread.currentThread().getName() + "完成总量：" + length);
                }
            } catch (MalformedURLException e) {
                System.out.println("url 格式化异常");
                e.printStackTrace();
            } catch (IOException e) {
                System.out.println("IO 流异常");
                e.printStackTrace();
            }finally {
                //无论成功失败，都标记线程完成
                countDownLatch.countDown();
                System.out.println(Thread.currentThread().getName() + "完成了！---" + length);
            }
        }
    }
}
